Thanks for this answer. The timeout box is enabled both on my machine and in your screenshot. Do you know how I can enable it?
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Vitaly MijiritskySep 14 '13 at 8:28

It's important to note that the webupd8 PPA has many other packages in it, so it might be overwriting other packages...
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MarkovCh1Feb 23 '14 at 2:03

A bit ridiculous that in 2014 you need to install a bunch of unofficial patches just to configure notifications, something that's a right click away on other OSes/desktop managers.
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Dan DascalescuNov 12 '14 at 18:53

In my tool there are 3 Checkbox options at the end of Bubble tab which is not shown in previous answer's image, these options worked for me, I'll suggest U recheck the procedure of installation of this tool.

In case anyone might come to this question sometime with a Lubuntu distro (or any other of the 'Buntu flavors), please note that things might be quite different there.
On Lubuntu, the best and quickest way is to use xfce4-notifyd-config; however, there is no way to have the notification dialog appear anywhere in the top center; merely the four corners are supported. But for those that don't need more, this will be sufficient by far to get the notification dialog out of the way when something else has been placed there and would constantly interfere resp. overlap.